Damned if I know what I am any more, but since I have two degrees in engineering, and an inspectors ticket, the word "Engineer" usually applies.
I'd vote for protection of the title - to at-least restrict the title to those with formal professional qualifications; I don't mind if that's CEng, LAME, or a 4-year apprenticeship at Dagenham - but I do object to its use by somebody who has done a 3 week course in servicing photocopiers.
G